This is a place for the free and honest exchange of ideas about many of the ecological and environmental issues that we face on regular basis. You are encouraged to contribute and share your thoughts with your colleagues in a frank but respectful style. The commentary is NOT moderated so please act responsibly. Let us prove Hardin wrong, at least in this space, cooperation is the way out of the tragedy of the commons!!!!
We have already posted ten "stories" that we promised to do during this semester. The following, however, is for extra credit and is the response of George Monbiot to a couple of questions. Enjoy
Why is implacable growth a threat to the existence of life on the planet?
Never-ending growth simply cannot be sustained on a finite planet. The promise of growth is used as a means of deflecting social conflict: If the economy keeps growing, we are told, inequality doesn't matter, however extreme it becomes, as all will be rich. Well, it hasn't worked out like that: The rich are now able to capture almost all the increment; wages have stagnated despite rising labor productivity; far from trickling down, wealth is still seeping upwards. But even if it did work, this merely exchanges a deferred political crisis for an environmental crisis.
In the pre-coal economy, industrial growth was repeatedly undermined by agricultural collapse, as both competed for the same resources: land (industry needed it for growing fuelwood and fodder for horses) and labor. So growth kept stalling and reversing. Coal meant that rather than relying on annual productivity (of timber, grass, oats etc.), industry could exploit the concentrated productivity of millions of years. It amplified the effects of labor. It allowed agriculture and industry to live alongside each other, ensuring that industrial growth did not rely on starvation. The economic transformation was miraculous. But it had a number of costs, and by far the greatest, in the long run, was the assault on the natural world.
We are urgently in need of a new, coherent economic model, that provides prosperity without compromising future prosperity, that does not rely on destroying the more-than-human world.
Why will a continuing "shift from small to large farms ... cause a major decline in global production"?
There is a long-established inverse relationship between the size of farms and the amount of crops they produce. In other words, the smaller they are, the greater the yield per hectare. This observation has been repeated in many parts of the world.
The most plausible explanation appears to be that small farmers use more labor, and more committed labor (generally family members), per hectare than big farmers.
What this means is that farm consolidation (often assisted by international agencies) is likely to be damaging to productivity, and threatening to world food supplies. Land grabbing by foreign corporations and sovereign wealth funds (which brings together the traditions of enclosure and colonialism) is disastrous for the rural poor. It is also disastrous -- especially when it results in the replacement of subsistence crops with crops grown for animal feed or biofuels -- for global food security.
Make the case for being "deviant and proud."
Our identity is shaped by the norms and values we absorb from other people. Every society defines and shapes its own according to dominant narratives, and seeks either to make people comply or to exclude them if they don't. These norms and values are often handed down from on high: We absorb and replicate the worldview of those who possess power, the phenomenon Antonio Gramsci called cultural hegemony.
Neoliberalism insists that we are defined by competition, and are essentially selfish and acquisitive. This turns out to be a myth: As a paper in the journal Frontiers in Psychology points out, Homo economicus -- the neoliberal conception of people as maximizing their own self-interest at the expense of others - is an excellent description of chimpanzees and a very bad description of human beings. We simply don't work like this. Humans are distinguished from other mammals by an enhanced capacity for empathy, an unparalleled sensitivity to the needs of others, a unique level of concern about their welfare and an ability to create moral norms that generalize and enforce these tendencies. These traits emerge so early in our lives that they appear to be innate: We have evolved to be this way.
But the dominant narrative tells us that we are very different creatures. It celebrates selfishness and greed and pushes us to conform to a social and economic model that rewards them. When we are forced into a hole that doesn't fit, the result is psychological damage. As the professor of psychoanalysis Paul Verhaeghe points out, the neoliberal transition has been accompanied by a spectacular rise in self-harm, eating disorders, depression, performance anxiety, social phobia and loneliness.
So if you don't fit in, and feel at odds with the world, it could be because you have retained the human values you were supposed to have discarded. You have deviated from the social norms. You should be proud to have done so.
The United States and China are the world's largest carbon emitters , so the 2014 agreement by U.S. President Barack Obama and Chinese President Xi Jinping to reduce their countries' greenhouse gas emissions represented a major shift in momentum for addressing the effects of climate change.
Both countries committed to substantial emissions-reduction efforts over the next 10 to 15 years, with the understanding that they would continue to grow more ambitious with their efforts in the future. The pledges were fundamental to each country's national commitments for the Paris Agreement, adopted during the United Nations' 2015 climate conference and awaiting signatures this month at the United Nations inNew York City.
Once a minimum of 55 countries representing at least 55 percent of total global greenhouse gases sign on, the agreement will come into effect. Already 100 countries are expected to attend the U.N. meeting on Earth Day this April 22.
An energy explosion
While China vowed to put a peak on its growing carbon dioxide emissions by the year 2030, a new report from the Grantham Research Institute on Climate Change and the London School of Economics and Political Science argues that the past year brought a changing economic and energy landscape. This is because China's rapid growth, which consumed tremendous amounts of energy and produced record-setting emissions, is slowing.
China's economic model over the past few decades — like that of many other developing countries — was based on heavy investment in construction and related industries, such as steel and cement, in order to expand the nation's infrastructure. Such industries are energy-intensive and in China relied heavily on coal, which produces large amounts of greenhouse gas emissions .
Now that much of China's infrastructure build-out is slowing, the demand for steel, cement and other building materials is decreasing, while at the same time China is expanding energy investments in hydroelectric, nuclear, wind and solar power.
In fact, the increase in China's renewable energy generation is expected be larger than energy-investment increases in the European Union, the United States and Japan combined, according to the 2013 World Energy Outlook from the International Energy Agency (IEA).
These promising shifts in energy investment are not unique to China. In the United States, the Energy Information Administration suggests that in the coming year, more new solar electricity-generating capacity will come online than natural gas, wind or petroleum combined.
Of that amount, two-thirds came from first-time buyers, according to the nonprofit Rocky Mountain Institute, a leading source on addressing climate change through market-based solutions. The most-promising trend shows older established companies — like Owens Corning, Procter & Gamble and HP — joining well-publicized new industry leaders like Amazon, Google and Ikea in making the transition toward renewable energy purchases. For example, last year, Owens Corning signed an agreement with Chicago-based Invenergy for 125 megawatts of capacity, equivalent to the power needed for 30,000 households or more, from a wind farm being built in Texas.
Beyond industry — beyond government — a third, large-scale stakeholder is innovating in the context of climate change: academia. Responding to a growing demand from their students and faculty to transition away from fossil fuels, colleges and universities such as Ohio State University and the University of Oklahoma are among the partners with the largest U.S. green power contracts, according to the U.S. Environmental Protection Agency.
Chinese energy evolution
Like recent progress in the United States and European Union, China's energy landscape has continued to diversify, according the Grantham report. Hydroelectric, nuclear, wind and solar power are all expanding and accounted for more than 11 percent of the nation's primary energy consumption by the end of 2014.
Perhaps most notably, coal consumption, which powered so much of China's forward momentum in the previous decade, saw no growth in 2014 and actually declined in 2015.
Whether China's emissions peak has actually crested, the trends there and elsewhere are becoming more evident: Nations and companies across the world are making the transition to clean energy alternatives and putting their money behind those investments in order to foster new, innovative paths to a lower-emission future.
Global perspectives have shifted toward encouraging nations to finally respond to climate change, but the window for action to avoid catastrophic climate impacts is limited. New technology is opening opportunities to reduce global emissions, and China's move toward renewable energies is at the forefront, such as their world-leading number of solar-voltaic installations for power generation.
It's up to the rest of the world to continue to look forward, not back, to enhance global prosperity, reduce risks to communities, and sustain healthy ecosystems on which people depend.
Eating more fruit and vegetables and cutting back on red and processed meat will make you healthier. That’s obvious enough. But as chickens and cows themselves eat food and burn off their own energy, meat is a also major driver of climate change. Going veggie can drastically reduce your carbon footprint.
This is all at a personal level. What about when you multiply such changes by 7 billion people, and factor in a growing population?
In our latest research, colleagues and I estimate that changes towards more plant-based diets in line with the WHO’s global dietary guidelinescould avert 5m-8m deaths per year by 2050. This represents a 6-10% reduction in global mortality.
Food-related greenhouse gas emissions would also be cut by more than two thirds. In all, these dietary changes would have a value to society of more than US$1 trillion – even as much as US$30 trillion. That’s up to a tenth of the likely global GDP in 2050. Our results are published in the journal PNAS.
Future projections of diets paint a grim picture. Fruit and vegetable consumption is expected to increase, but so is red meat consumption and the amount of calories eaten in general. Of the 105 world regions included in our study, fewer than a third are on course to meet dietary recommendations.
A bigger population, eating a worse diet, means that by 2050 food-related GHG emissions will take up half of the “emissions budget” the world has for limiting global warming to less than 2℃.
To see how dietary changes could avert such a doom and gloom scenario, we constructed four alternative diets and analysed their health and environmental impacts: one reference scenario based on projections of diets in 2050; a scenario based on global dietary guidelines which includes minimum amounts of fruits and vegetables, and limits to the amount of red meat, sugar, and total calories; and two vegetarian scenarios, one including eggs and dairy (lacto-ovo vegetarian), and the other completely plant-based (vegan).
Millions of avoidable deaths
We found that adoption of global dietary guidelines could result in 5.1m avoided deaths per year in 2050. Vegetarian and vegan diets could result in 7.3m and 8.1m avoided deaths respectively. About half of this is thanks to eating less red meat. The other half comes thanks to eating more fruit and veg, along with a reduction in total energy intake (and the associated decreases in obesity).
There are huge regional variations. About two thirds of the health benefits of dietary change are projected to occur in developing countries, in particular in East Asia and South Asia. But high-income countries closely follow, and the per-person benefits in developed countries could actually be twice as large as those in developing countries, as their relatively more imbalanced diets leave greater room for improvement.
China would see the largest health benefits, with around 1.4m to 1.7m averted deaths per year. Cutting red meat and reducing general overconsumption would be the most important factor there and in other big beneficiaries such as the EU and the US. In India, however, up to a million deaths per year would be avoided largely thanks to eating more fruit and vegetables.
Russia and other Eastern European countries would see huge benefits per-person, in particular due to less red meat consumption. People in small island nations such as Mauritius and Trinidad and Tobago would benefit due to reduced obesity.
Vegans vs climate change?
We estimated that adopting global dietary guidelines would cut food-related emissions by 29%. But even this still wouldn’t be enough to reduce food-related greenhouse gas emissions in line with the overall cutbacks necessary to keep global temperature increases below 2°C.
To seriously fight climate change, more plant-based diets will be needed. Our analysis shows if the world went vegetarian that cut in food-related emissions would rise to 63%. And if everyone turned vegan? A huge 70%.
What’s it worth?
Dietary changes would have huge economic benefits, leading to savings of US$700-1,000 billion per year globally in healthcare, unpaid informal care and lost working days. The value that society places on the reduced risk of dying could even be as high as 9-13% of global GDP, or US$20-$30 trillion. Avoided climate change damages from reduced food-related greenhouse gas emissions could be as much as US$570 billion.
Putting a dollar value on good health and the environment is a sensitive issue. However, our results indicate that dietary changes could have large benefits to society, and the value of those benefits makes a strong case for healthier and more environmentally sustainable diets.
The scale of the task is clearly enormous. Fruit and vegetable production and consumption would need to more than double in Sub-Saharan Africa and South Asia just to meet global dietary recommendations, whereas red meat consumption would need to be halved globally, and cut by two thirds in richer countries. We’d also need to tackle the key problem of overconsumption. It’s a lot to chew on.
DURING the summer of 1940, I was an 11year old living with my family in a
low income apartment in Washington, D.C. We were within easy walking
distance of the National Zoo and an adjacent strip of woodland in Rock Creek
Park. I lived most of my days there, visiting exotic animals and collecting
butterflies and other insects with a net that I had fashioned from a broom
handle, coat hanger and cheesecloth. I read nature books, field guides and past
volumes of National Geographic. I had already conceived then of a world of life
awaiting me, bottomless in variety.
Seventysix years later, I have kept that dream. As a teacher and scientist I
have tried to share it. The metaphor I offer for biological diversity is the magic
well: The more you draw, the more there is to draw.
But today the dream is at risk. Civilization is at last turning green, albeit
only pale green. Our attention remains focused on the physical environment —
on pollution, the shortage of fresh water, the shrinkage of arable land and, of
course, the great, wrathful demon that threatens all our lives, human forced
climate change. But Earth’s living environment, including all its species and all
the ecosystems they compose, has continued to receive relatively little attention. This is a huge strategic mistake. If we save the living environment of
Earth, we will also save the physical, nonliving environment, because each
depends on the other. But if we work to save only the physical environment, as
we seem bent on doing, we will lose them both.
So, what exactly is the current condition of the living environment, in
particular its biological diversity and stability? How are we handling this
critical element of Earth’s sustainability?
To begin, how many species of organisms are known on the planet? Here,
our knowledge is pathetically weak. At the present time, about two million
species have been discovered, described and given a Latinized scientific name.
But how many are there actually, known and unknown? Putting aside the
bacteria and a distinctive group of microbes called the archaea (which I like to
call together the dark matter of biology because so little is understood of their
diversity), the best estimate we have of all the rest (the fungi, algae, plants and
animals) is roughly 10 million, give or take a million.
Except for the vertebrates (consisting of 63,000 described species of
birds, mammals, reptiles, amphibians and fishes) and the flowering plants
(with approximately 270,000 species), relatively little is collectively known
about millions of kinds of fungi, algae and most diverse of all, the insects and
other invertebrate animals. And that matters, a lot: These least understood
minions are the foundation of the living world. They are the little things that
run the Earth.
In short, we live on a little known planet. E.T. and other alien biologists
visiting Earth would, I suspect, be appalled at our weak knowledge of our
homeland. They would be mystified by the scant attention humanity gives to
the lifeforms on which our existence depends.
The one major reserve in the United States that has been subjected to a
complete census is the Great Smoky Mountains National Park. Fifty thousand
hours of field work there by specialists and assistants have yielded records of
3/13/2016 The Global Solution to Extinction The New York Times
18,000 species of animals and microorganisms alone, with 40,000 to 60,000
considered likely on the roster when all transients, as well as rare and
undescribed species, have been registered.
The mapping of Earth’s biodiversity was not, as many assume, mostly
completed in the 19th and 20th centuries. It has only begun. The study of
biological diversity is absurdly slow. Today, only about 18,000 new species are
being discovered and described each year. If we continue at this rate (I’ve
described only about 450 new ant species in my own lifetime), the task of
mapping life on Earth, or what is left of it, will not be completed until the 23rd
That brings me to the extinction rate of species around the world. With
data on the best known vertebrate species, and a lot of additional information
from fossil studies and genetics, we can put the fraction of species
disappearing each year at upward of a 1,000 times the rate that existed before
the coming of humans.
Most of this loss is occurring in tropical countries, and especially tropical
forests on islands. But to bring it home to the United States, consider that
from 1895 to 2006, 57 species and distinct geographic races of freshwater
fishes were driven to extinction, which is 10 percent of the total previously
alive; hence the rate of extinction was just under 900 times that which existed
before the coming of humans.
The global conservation movement, pioneered by the United States, has
raised awareness of nature’s plight, and stimulated a great deal of excellent
research. It has slowed the hemorrhaging of species, but is still a long way
from stopping it. Conservation efforts are concentrated on the roughly one fifth
of vertebrate species worldwide that are ranked as endangered to some
degree. We have managed to stabilize or reverse the decline of onefifth of the
species in this group. A better record has been achieved within the United
States by the Endangered Species Act of 1973, which has brought more species back to health than have been lost in the same time period to
All this is progress, but the prospects for the rest of the century remain
grim. The global conservation movement is like a surgeon in an emergency
room treating an accident victim: He has slowed the bleeding by half.
Congratulations, we might say — even though the patient will be dead by
Unless we wish to pauperize the natural world drastically and
permanently, believing that later generations will be smart enough to find a
way to bring equilibrium to the land, seas and air, then we, the current
inheritors of this beautiful world, must take more serious action to preserve
the rest of life.
There is only one rational way to accomplish this goal, and that is to bring
the extinction rate back to the level that existed before the worldwide
expansion of human populations. The disappearance of natural habitat is the
primary cause of biological diversity loss at every level — ecosystems, species
and genes, all of them. Only by the preservation of much more natural habitat
than previously envisioned can extinction be brought close to a sustainable
The only way to save upward of 90 percent of the rest of life is to vastly
increase the area of refuges, from their current 15 percent of the land and 3
percent of the sea to half of the land and half of the sea. That amount, as I and
others have shown, can be put together from large and small fragments
around the world to remain relatively natural, without removing people living
there or changing property rights. This method has been tested on a much
smaller scale at the national and state park levels within the United States.
This step toward sustained coexistence with the rest of life is partly a
practical challenge and partly a moral decision. It can be done, and to great
and universal benefit, if we wish it so. I have to think that the dream of a boy from so long ago has a chance to
Edward O. Wilson, a professor emeritus at Harvard University, is the author of
“Half Earth: Our Planet’s Fight for Life.”
Comments due by March 14, 2016
— In the expanding realm ruled by Randal J. Kirk,
sliced apples don’t brown. Salmon grow twice as fast without swimming
upriver to spawn. Beloved cats are reborn.
And male mosquitoes are unleashed with the sole mission to mate, pass
on a gene that kills their offspring, and die.
A few decades ago, the foods and creatures nurtured by Mr. Kirk would
have been found only in dystopian fantasies like those written by Margaret
Atwood. But Mr. Kirk’s company, Intrexon, is fast becoming one of the world’s
most diverse biotechnology companies, with ventures ranging from unloved
genetically engineered creatures to potential cancer cures and gene therapies,
gasoline substitutes, cloned kittens and even glowinthedark Dino Pet toys
made from microbes.
Until recently, Mr. Kirk, 62, was a relatively unknown, self made
billionaire, buying up or investing in companies in the biotech world. So when
Intrexon acquired the British company Oxitec last summer, it attracted little attention as he extended his reach into genetically modified insects.
But that move has thrust Mr. Kirk into the forefront of a scramble to
control the Zika virus, suspected of causing babies to be born with tiny heads
and damaged brains. It is rampant in Latin America and threatening the
While Zika was not on his radar when the deal was announced, Mr. Kirk
now appears to be the prescient owner of a potential bioweapon — Oxitec’s
genetically engineered mosquitoes, which he says could save millions of people
from Zika by causing the population of wild disease transmitting mosquitoes
to self destruct.
“I think that we have the only safe, effective, field proven and readyto-deploy
solution,” Mr. Kirk, who is usually called R.J., said in an interview in
his office here overlooking the Intracoastal Waterway. In Piracicaba, Brazil,
the population of wild mosquitoes has fallen 82 percent in the neighborhood
where the mosquitoes are being tested, he said.
If his plans to sell the engineered mosquitoes succeed, Mr. Kirk will fortify
his near cultlike status among some investors and colleagues who marvel at
his shrewd (and somewhat lucky) investments.
Perhaps more important, a victory against the rapidly spreading epidemic
could weaken opposition to genetically engineered organisms of all sorts,
propelling many others out of the lab, onto the dinner table or into the
Now Mr. Kirk must persuade federal agencies, foreign governments and
nonprofit health organizations to place orders. He must counter caution from
the World Health Organization and federal officials, who question whether the
technique will be effective on a large scale. And he must overcome qualms
about genetic engineering that have prompted opposition to the mosquitoes in
the Florida Keys and elsewhere.
“We don’t have experience about living transgenic mosquitoes in the air,”
said Dr. Artur Timerman, an infectious disease specialist in Brazil. “What will
be the midterm or long term consequences of this?”
Mr. Kirk is assembling a powerful lobbying effort, employing the law firm
Sidley Austin in Washington as well as relying on one of Intrexon’s board
members, Cesar Alvarez, the senior chairman of the prominent law firm
Greenberg Traurig, and Intrexon’s head of corporate communications, Jack
Bobo, who once directed biotechnology trade policy at the State Department.
Dr. Luciana Borio, acting chief scientist at the Food and Drug
Administration, told a House subcommittee on Wednesday that the agency
was “greatly expediting” Oxitec’s application to test the mosquitoes in the
Florida Keys and would issue a draft environmental assessment very soon.
But when asked by Representative Morgan Griffith, a Republican who
represents the Virginia district in which Mr. Kirk has a farm, Dr. Borio said the
F.D.A. would not eliminate the opportunity for the public to then comment on
“What we don’t know right now is where the public stands on this in the
setting of Zika,” she said later in the hearing.
Golden Age of Biotech
Selling his mosquitoes to combat an international epidemic could help
relieve the pressure Mr. Kirk is under to prove that Intrexon is more than just
a collection of odd science projects, and that it can actually make money and
fulfill his vision for a new golden age of biotechnology.
He considers this time to be a seminal moment in history, one in which
the rapidly improving ability to read and write — and rewrite — the DNA code
of life will make it possible to engineer all manner of organisms to perform
“I think this is the most significant industrial vector to occur in history,”
he said, comparing it to semiconductor technology that gave rise to
smartphones and the web.
And the same DNA tools can be applied to numerous areas. Intrexon’s
scientists, he says, “don’t care if they are working on a primary human T cell or
an avocado.” Reflecting that vision, Intrexon uses the web domain name
The engineering of life is often called synthetic biology, a vaguely defined
term meant to convey more systematic genetic manipulation than the cutting
and pasting of a single gene that gave rise to early biotechnology companies
like Amgen and Genentech. At its most distant point, synthetic biologists
would sit at a computer designing life forms from scratch, then hit “print” and
have the necessary DNA made to order to be inserted into a cell.
Numerous companies are moving into the field, but Intrexon is “literally
the elephant in the room of the synthetic biology industry,” said John
Cumbers, chief executive of SynBioBeta, a fledgling trade group.
His supporters say that if anyone can pull off such an enterprise it is R. J.
Kirk, whom they call an uncommon visionary and quick study, though he lacks
formal training in science. When Mr. Kirk tells people, as he often does, that
he is just a country lawyer, they know they’re about to get a schooling in
biology or business, interlaced with references to history, philosophy and
“He has an astonishing grasp of science,” said Dr. Samuel Broder, a
former director of the National Cancer Institute who now runs Intrexon’s
health division. Dr. Broder recalled one instance in which it took him a day to
understand the intricacies of a genetic disease. Mr. Kirk, after hearing Dr.
Broder’s explanation, got it in five minutes.
Even the hedge fund manager Thomas U. Barton, who made his mark as a skeptical shortseller, gushes. “He understands all businesses,” he said.
Still, there are skeptics. It is hard to judge the strength of Intrexon’s core
technology, known as UltraVector, which is a computerized system for putting
together modular DNA pieces to make complex genetic circuits. The company,
saying it wants to protect its trade secrets, has not published articles about it
in scientific literature. Some startup companies, not Intrexon, have taken the
lead in the hot new genome editing technique called Crispr.
The biggest criticism is that Intrexon keeps announcing new acquisitions
and new collaborations, dozens of them in all. Yet no product made with the
company’s technology has reached the market, and it is not clear when any
“There’s a mixture here of spectacle and speculation,” said Jim Thomas of
the nonprofit ETC Group, which says that synthetic biology needs to be more
rigorously regulated. “What’s curious about this is the way in which they are
putting together all these controversial and often failing one
and trying to wrap them up in a fancy synthetic biology front.”
Intrexon’s shares have fallen to about $37 from near $70 in July, though
biotech stocks in general have also fallen. The company’s market value is $4.3
billion, making Mr. Kirk’s 53 percent worth over $2 billion.
One big commercial opportunity could be Intrexon’s pilot project to use
genetically altered microbes to turn natural gas, which is cheap and abundant,
into isobutanol, a liquid fuel that can be used in cars. Investors want to see if
Intrexon’s partner, the energy giant Dominion, commits to building a
commercial plant, which Mr. Kirk hopes could happen as early as this year.
And the Oxitec mosquitoes, while not something Intrexon developed
itself, offer a bonus that Mr. Kirk could not have predicted. The mosquitoes
were developed mainly to fight dengue fever, and that alone, Mr. Kirk said,
made it worthwhile to pay about $160 million for Oxitec.
3/6/2016 A Biotech Evangelist Seeks a Zika Dividend The New York Times
But because Zika is spread by the same type of mosquito, the Oxitec
insects, which contain a lethality gene — can be used. When the male
mosquitoes are released to mate with wild females, the offspring die before
Protected areas such as rainforests occupy more than one-tenth of the Earth’s landscape, and provide invaluable ecosystem services, from erosion control to pollination to biodiversity preservation. They also draw heat-trapping carbon dioxide (CO2) from the atmosphere and store it in plants and soil through photosynthesis, yielding a net cooling effect on the planet.
Determining the role protected areas play as carbon sinks — now and in decades to come — is a topic of intense interest to the climate-policy community as it seeks science-based strategies to mitigate climate change. Toward that end, a study in the journal Ambio estimates for the first time the amount of CO2 sequestered by protected areas, both at present and throughout the 21st century as projected under various climate and land-use scenarios.
Based on their models and assuming a business-as-usual climate scenario, the researchers projected that the annual carbon sequestration rate in protected areas will decline by about 40 percent between now and 2100. Moreover, if about one-third of protected land is converted to other uses by that time, due to population and economic pressures, carbon sequestration in the remaining protected areas will become negligible.
“Our study highlights the importance of protected areas in slowing the rate of climate change by pulling carbon dioxide out of the atmosphere and sequestering it in plants and soils, especially in forested areas,” said Jerry Melillo, the study’s lead author. Melillo is a distinguished scientist at the Marine Biological Laboratory (MBL) in Woods Hole, Massachusetts, and former director of the MBL’s Ecosystems Center. “Maintaining existing protected areas, enlarging them and adding new ones over this century are important ways we can manage the global landscape to help mitigate climate change.”
Based on a global database of protected areas, a reconstruction of global land-use history, and a global biogeochemistry model, the researchers estimated that protected areas currently sequester 0.5 petagrams (500 billion kilograms) of carbon each year, or about 20 percent of the carbon sequestered by all land ecosystems annually. Using an integrated modeling framework developed by the MIT Joint Program on the Science and Policy of Global Change, they projected that under a rapid climate-change scenario that extends existing climate policies; keeps protected areas off-limits to development; and assumes continued economic growth and a 1 percent annual increase in agricultural productivity, the annual carbon sequestration rate in protected areas would fall to about 0.3 petagrams of carbon by 2100.
When they ran the same scenario but allowed for possible development of protected areas, they projected that more than one-third of today’s protected areas would be converted to other uses. This would reduce carbon sequestration in the remaining protected areas to near zero by the end of the century. (The protected areas that are not converted would be the more marginal systems that have low productivity, and thus low capacity to sequester carbon.)
Based on this analysis, the researchers concluded that unless current protected areas are preserved and expanded, their capacity to sequester carbon will decline. The need for expansion is driven by climate change: As the average global temperature rises, so, too, will plant and soil respiration in protected and unprotected areas alike, thereby reducing their ability to store carbon and cool the planet.
“This work shows the need for sufficient resources dedicated to actually prevent encroachment of human activity into protected areas,” said John Reilly, one of the study’s coauthors and the co-director of the MIT Joint Program on the Science and Policy of Global Change.
The study was supported by the David and Lucille Packard foundation, the National Science Foundation, the U.S. Environmental Protection Agency, and the U.S. Department of Energy.
Virtually everyone in the scientific community agrees that ensuring sufficient food supplies for a surging human population, which is set to grow by 2.4 billion by mid-century, will require serious work. Indeed, we have not even succeeded at providing enough food for today’s population of 7.3 billion: Nearly 800 million people currently are starving or hungry, and another couple billion do not get enough micronutrients. But there is no such consensus about how to address the food-security problem.
The scientific community is split between two main approaches: “tinker with agricultural details” (TAD) and “mend societal fundamentals” (MSF). While the former approach has support from a clear majority, the latter is more convincing.
To be sure, the TAD camp has identified many important problems with current food production and distribution systems, and addressing them could indeed improve food security. Yields could be increased by developing better crop varieties. Water, fertilizer, and pesticides should be used more efficiently. Maintaining tropical forests and other relatively natural ecosystems would preserve critical ecosystem services, especially soil fertility, pollination, pest control, and climate amelioration. The trend toward rising meat consumption should be reversed. Stricter regulation of fisheries and ocean pollution would maintain the supply of marine protein essential to many people. Waste in food production and distribution should be reduced. And people should be educated to choose more sustainable and nutritious foods.
Achieving these goals, TAD supporters recognize, would require policymakers to give food security high political and fiscal priority, in order to support the needed research and action. Responsibility for launching programs to distribute food more equitably would also fall to governments.
But the TAD approach is incomplete. Not only would its short-term goals be extremely difficult to achieve without more fundamental societal changes; even if they were attained, they would probably prove inadequate in the medium term, and certainly in the long term.
To see why, let us suppose that, in 2050, the TAD goals have all been reached. More food is available, thanks to higher agricultural yields and waste-reducing improvements in storage and distribution. Improved environmental policies mean that most of today’s forests are still standing and no-fishing zones are widely established and enforced. Ecosystems are becoming stronger, with many corals and plankton evolving to survive in warmer, more acidic water. Add an uptick in vegetarianism, and it appears that the global temperature rise could be limited to 3º Celsius.
As a result, the world could avoid famines by mid-century. But, in a human population of 9.7 billion, hunger and malnutrition would be proportionately the same as they are in today’s population of 7.3 billion. In other words, even with such an extraordinary and unlikely combination of accomplishments and good luck, our food-security predicament would still be with us.
The reason is simple: Our societies and economies are based on the flawed assumption that perpetual growth is possible on a finite planet. To ensure global food security – not to mention other fundamental human rights – for all, we need to recognize our limitations, in terms of both social and biophysical factors, and do whatever it takes to ensure that we do not exceed them.
Based on this conviction, the MSF approach demands that governments take steps to empower women in all areas of society, and ensure that all sexually active people have access to modern birth control, with women free to have an abortion, if they so choose. At the same time, governments must address inequality of wealth, and thus of food, not least by curbing corporate dominance.
Short of bringing the global population down to sustainable levels, MSF reforms are the world’s only hope. But, as it stands, implementing them seems unlikely. The United States, the country that consumes the most, is moving in the opposite direction: women are struggling to hold onto their reproductive rights, wealth distribution is becoming increasingly skewed, and corporations are becoming even more powerful.
If this trend continues, in 2050, governance systems will be even more poorly equipped to deal with the fundamental problems of perpetual population and consumption growth or wealth inequality. As environments deteriorate from climate change, toxification, and loss of biodiversity and ecosystem services, people will have less time and energy for governance reform aimed at reducing inequality or preserving the environment. As a result, those in power will feel less pressure to arrange systems to provide food to those who need it most.
The social-biophysical system is replete with chicken-and-egg subsystems. Given that there is no obvious single vulnerable point in the system to initiate change, governments must address a range of issues simultaneously. Key starting points include purging politics of “big money”; introducing a more progressive tax system that effectively caps the income of the extremely wealthy; ensuring that policymakers have a basic level of scientific understanding; and strengthening women’s rights, including access to free contraception.
Just as social and environmental problems can be mutually reinforcing, so can actions aimed at strengthening our social and environmental fundamentals. Only by focusing on these fundamentals, rather than merely tinkering with the details of food production, can intrinsic systemic linkages work to the advantage of future generations.
EVEN if you’re not in Flint, Mich., there are toxic chemicals in your home. For
that matter, in you.
Scientists have identified more than 200 industrial chemicals — from
pesticides, flame retardants, jet fuel — as well as neurotoxins like lead in the
blood or breast milk of Americans, indeed, in people all over our planet.
These have been linked to cancer, genital deformities, lower sperm count,
obesity and diminished I.Q. Medical organizations from the President’s Cancer
Panel to the International Federation of Gynecology and Obstetrics have
demanded tougher regulations or warned people to avoid them, and the cancer
panel has warned that “to a disturbing extent, babies are born ‘prepolluted.’”
They have all been drowned out by chemical industry lobbyists.
So we have a remarkable state of affairs:
■ Politicians are (belatedly!) condemning the catastrophe of lead
poisoning in Flint. But few acknowledge that lead poisoning in many places in America is even worse than in Flint. Kids are more likely to suffer lead
poisoning in Pennsylvania or Illinois or even most of New York State than in
Flint. More on that later.
■ Americans are panicking about the mosquitoborne Zika virus and the
prospect that widespread infection may reach the United States. That’s a
legitimate concern, but public health experts say that toxic substances around
us seem to pose an even greater threat.
“I cannot imagine that Zika virus will damage any more than a small
fraction of the total number of children who are damaged by lead in
deteriorated, poor housing in the United States,” says Dr. Philip Landrigan, a
prominent pediatrician and the dean for global health at the Icahn School of
Medicine at Mount Sinai.
“Lead, mercury, PCBs, flame retardants and pesticides cause prenatal
brain damage to tens of thousands of children in this country every year,” he
Yet one measure of our broken political system is that chemical
companies, by spending vast sums on lobbying — $100,000 per member of
Congress last year — block serious oversight. Almost none of the chemicals in
products we use daily have been tested for safety.
Maybe, just maybe, the crisis in Flint can be used to galvanize a public
In 1854, a British doctor named John Snow started such a revolution.
Thousands were dying of cholera at the time, but doctors were resigned to the
idea that all they could do was treat sick patients. Then Snow figured out that a
water pump on Broad Street in London was the source of the cholera. The
water company furiously rejected that conclusion, but Snow blocked use of the
water pump, and the cholera outbreak pretty much ended.
This revelation led to the germ theory of disease and to investments in
sanitation and clean water. Millions of lives were saved.
Now we need a similar public health revolution focusing on the early roots
of many pathologies.
For example, it’s scandalous that 535,000 American children ages 1 to 5
still suffer lead poisoning, according to the Centers for Disease Control and
Prevention. The poisoning is mostly a result of chipped lead paint in old
houses or of leadcontaminated soil being tracked into homes, although some
areas like Flint also have tainted tap water.
While the data sets are weak, many parts of America have even higher
rates of child lead poisoning than Flint, where 4.9 percent of children tested
have had elevated lead levels in their blood. In New York State outside New
York City, it’s 6.7 percent. In Pennsylvania, 8.5 percent. In part of Detroit, it’s
20 percent. The victims are often poor or black.
Infants who absorb lead are more likely to grow up with shrunken brains
and diminished I.Q. They are more likely as young adults to engage in risky
sexual behavior, to disrupt school and to commit violent crimes. Many
researchers believe that the worldwide decline in violent crime beginning in
the 1990s is partly a result of lead being taken out of gasoline in the late 1970s.
The stakes are enormous, for individual opportunity and for social cohesion.
Fortunately, we have some new Dr. Snows for the 21st century.
A group of scholars, led by David L. Shern of Mental Health America,
argue that the world today needs a new public health revolution focused on
young children, parallel to the one mounted for sanitation after Snow’s
revelations about cholera in 1854. Once again, we have information about how
to prevent pathologies, not just treat them — if we will act.
The reason for a new effort is a vast amount of recent research showing that brain development at the beginning of life affects physical and mental
health decades later. That means protecting the developing brain from
dangerous substances and also from “toxic stress” — often a byproduct of
poverty — to prevent high levels of the stress hormone cortisol, which impairs
A starting point of this public health revolution should be to protect
infants and fetuses from toxic substances, which means taking on the
companies that buy lawmakers to prevent regulation. Just as water companies
tried to obstruct the 19th century efforts, industry has tried to block recent
Back in 1786, Benjamin Franklin commented extensively on the perils of
lead poisoning, but industry ignored the dangers and marketed lead
aggressively. In the 1920s, an advertisement for the National Lead Company
declared, “Lead helps to guard your health,” praising the use of lead pipes for
plumbing and lead paint for homes. And what the lead companies did for
decades, and the tobacco companies did, too, the chemical companies do
Lead poisoning is just “the tip of the iceberg,” says Tracey Woodruff, an
environmental health specialist at the University of California at San
Francisco. Flame retardant chemicals have very similar effects, she says, and
they’re in the couches we sit on.
The challenge is that the casualties aren’t obvious, as they are with
cholera, but stealthy and long term. These are silent epidemics, so they don’t
generate as much public alarm as they should.
“Industrial chemicals that injure the developing brain” have been linked
to conditions like autism and attention deficit hyperactivity disorder, noted
The Lancet Neurology, a peer reviewed medical journal. Yet we still don’t have
a clear enough sense of what is safe, because many industrial chemicals aren’t
safety tested before they are put on the market. Meanwhile, Congress has dragged out efforts to strengthen the Toxic Substances Control Act and test
more chemicals for safety.
The President’s Cancer Panel recommended that people eat organic if
possible, filter water and avoid microwaving food in plastic containers. All
good advice, but that’s like telling people to avoid cholera without providing
And that’s why we need another public health revolution in the 21st
century. (N. Kristof)
It was a gray, damp January afternoon a few years back when I visited the
Jiangfeng wholesale poultry market on the outskirts of Guangzhou, in the
southern Chinese province of Guangdong. With its bleak wire enclosures and
grid of cement paths, the place had the feel of a neglected 1970s era urban zoo.
And despite the comparatively narrow range of species there — chickens,
geese, ducks, quails and partridges, mostly, with a smattering of rabbits and
one large slumbering hog — it smelled like one, too. As I walked around,
watched suspiciously by the market’s handsome young security guards, a slimy
mix of bird droppings and decomposing feathers slowly crept up the heels of
Every few months, it seems, an invasive virus from a distant land attacks
the Americas: dengue, chikungunya and, most recently, Zika. But the
pathogens that frighten me most are novel strains of avian influenza.
I’d come to see their birthplace. Highly virulent and easily transmissible,
these viruses emerge from openair poultry farms and markets of the kind that stretch across Asia. Thanks to rising demand for chicken and other poultry,
they’ve been surfacing at an accelerated clip, causing nearly 150 percent more
outbreaks in 2015 than in 2014. And in late 2014, one strain managed to cross
the ocean that had previously prevented its spread into the Americas,
significantly expanding its reach across the globe.
Novel avian influenza viruses are mongrels, born when the influenza
viruses that live harmlessly inside the bodies of wild ducks, geese and other
waterfowl mix with those of domesticated animals like the ones at Jiangfeng,
especially poultry but also pigs. It’s possible to squelch their emergence. One
way is to protect domesticated animals from the excreta of waterfowl, which
can spread infection. But no such protections are in effect at markets such as
Jiangfeng, which, like the rest of southern China’s booming poultry industry,
lies within the East Asian flyway, one of the world’s most important waterbird
The poultry enclosures are open to the air. Droppings from the birds in
cages as well as the birds flying overhead coat the floor. Stonyfaced women
with shovels push the mess into reeking, shoulder height heaps of wet mush.
Any virus that lurks in those piles can easily spread to the birds and the people
who tend them. Up to 10 percent of poultry workers in Hong Kong, a study has
found, have been exposed to bird flu. A fine dust of desiccated bird waste
permeates the air. It settles on the leaves of the workers’ makeshift vegetable
plots behind the cages and on the window panes of their nearby flats.
These markets and the unique viral ecology they enable are not new, as
Malik Peiris, a virologist at the University of Hong Kong, points out. But “now
the situation is very different,” he said. “This is being done on a much bigger
scale than it was years ago.”
As health conscious consumers in the West cut beef out of their diets and
newly affluent Asians add more meat to theirs, demand for bird flesh has
skyrocketed. Global poultry production has more than quadrupled since 1970. And nowhere has the taste for poultry risen faster than in Asia, where chicken
farming expanded by nearly 4.5 percent a year from 2000 to 2012. China now
consumes more chicken than the United States. Tyson Foods aims to double
production in China. “We just can’t build the houses fast enough,” Donnie
Smith, the company’s chief executive, said to The Wall Street Journal,
referring to poultry production buildings, and “we’re going absolutely as fast
as we know how to go.”
It’s not just the growing scale of the poultry industry in Asia that increases
the probability that new avian influenza viruses will emerge. It’s also the
peculiar nature of the trade. About half of China’s poultry trade traffics in live
birds. That’s because many Chinese consumers, wary of the safety of frozen
meats, prefer to buy their chickens while they’re still clucking. This creates a
wealth of opportunities for new viral strains to spread and adapt to human
bodies. Rather than visiting the sterile frozen food aisles of grocery stores,
shoppers crowd into poultry markets, exposing themselves to live birds and
their viral laden waste. And to serve the markets, more birds travel from farms
into towns and cities, broadcasting viruses along the way.
Most novel strains of avian influenza cannot infect humans. But some can,
including three currently circulating strains: H5N1, a mashup of viruses from
geese and quail; H7N9, an amalgam of viruses from ducks, migratory birds
and chickens; and H10N8, the product of viruses from wild birds, ducks and
chickens. These viruses kill roughly 30 percent to 60 percent of their reported
human victims. None can spread efficiently from one person to another, for
example through sneezes and coughs, yet. But, given the opportunity, they will
continue to evolve. And if they finetune their transmissibility among humans,
the result will almost certainly be the kind of pandemic that epidemiologists
most fear — one that could sicken a billion, kill 165 million and cost the global
economy up to $3 trillion.
A majority of experts predicted, in a 2006 survey, that a pandemic would
occur within two generations. That prediction is based, in part, on the increasing number of novel strains of avian influenza and the accelerating
speed of their emergence. It’s also based on history. The virus that caused the
influenza pandemic of 2009 killed an estimated 200,000 people, hitting young
people in the Americas hardest. It originated in birds. So did the 1918 flu,
which killed 50 million, including an estimated 675,000 Americans.
For years, experts considered the Americas comfortably isolated from the
virulent avian influenza viruses hatched on distant Asian poultry farms and
markets. “Being in North America,” said Carol Cardona, an avian disease
expert at the University of Minnesota, “we weren’t bothered.”
Some of the novel strains of avian influenza emerging from the Asian
poultry trade can be picked up and spread far and wide by migratory birds. But
the migratory routes of these birds don’t cross the oceans. Even as they spread
H5N1 and other pathogens into dozens of countries in Europe, Asia and Africa,
the Americas remained untouched.
That changed in late 2014, when a highly virulent avian influenza from
Asia infiltrated North America. Its prospects here differed from those in Asia.
Relatively few people are regularly exposed to live poultry and their waste. And
farmers protect their domesticated flocks from pathogens by screening and
controlling ventilation in barns and by regularly disinfecting farm equipment.
Remarkably, none of these safeguards arrested the virus’s inexorable
spread. It was as if the virus “knew the weaknesses of each individual farm,”
said Dr. Cardona, “and found that and exploited it.” Infected farms euthanized
entire flocks by smothering them with carbon dioxide or firefighting foam.
From December 2014 to last June, more than 48 million domesticated poultry
in 21 states were slaughtered, the majority in waterfowl rich Minnesota and
Iowa, in what the Department of Agriculture called the worst animal disease
epidemic in United States history. By the time it ended, a 12 foot wide ridge of
bird carcasses from a single farm in Iowa stretched more than six miles.
Nobody knows just how this virus migrated over the oceans protecting the New World. But it’s possible that another consequence of human appetites —
climate change — played a role.
While Asian and European birds don’t migrate into North America, they
can pass on viruses to birds that do. That could happen in a place where
millions of birds from both the Old World and New World are instinctively
drawn every spring: the Arctic lands surrounding the Bering Strait, known as
In the past, New and Old World birds in Beringia visited numerous ponds
spread out across the tundra. But with temperatures in the Arctic rising twice
as fast as anywhere else, conditions are changing rapidly, shifting the
distribution of creatures and their pathogens. Historically segregated species
are coming into novel kinds of contact. As birds are forced to migrate earlier
and farther, feeding at new times and in new places, they overlap with other
bird species in unprecedented ways that pathogens can exploit.
Some already have. In 2012, a parasitic roundworm normally found some
1,000 miles southeast turned up in birds in western Alaska. In 2013, birds in
Alaska suffered their first epidemic of avian cholera, which typically infects
birds in the lower 48 states.
WHILE the precise conditions under which the virulent Asianorigin virus
arrived in North America in 2014 remain murky, what’s known is this:
Migratory birds picked up the virus from a poultry farm in Asia, carrying it
with them into Siberia and Beringia for the breeding season. There, whether it
was because of the new intimacy of the changed landscape, or because of
something about the virus itself, the pathogen spread into other bird species,
including those that would later head into North America, such as gyrfalcons
and northern pintail ducks. By December 2014, they had brought the virus
into British Columbia, Washington and Oregon, infecting wild and
domesticated birds along the way and igniting the epidemic.
If this strain had been one that could infect humans, a deadly and disruptive public health emergency would have ensued. Luckily, it was not.
But there are more where it came from, at the growing interface between
live poultry and humans on the other side of the Pacific. The workers at
Jiangfeng, with their bare hands and tall boots, toil at its border. I watched
them in the crowded enclosures as they lassoed birds around the neck with
long, curved poles, stuffing them into plastic bins and loading them onto
trucks. When a security guard caught me staring, I quickly walked away,
footsteps muted by the membrane of bird waste encasing the soles of my
shoes. Perhaps I could scrounge some bleach solution at my hotel with which
to sterilize them, I thought to myself, although of course the birds whose lives
and peregrinations are shaped by our appetites would not be so circumspect.
As I padded toward the exit, a stream of vehicles crammed with fowl, and
whatever viruses replicated inside their feathery bodies, steadily rumbled out
of the market, bound for points unknown.
There are more than 7 billion people on Earth now, and roughly one in eight of us doesn't have enough to eat. The question of how many people the Earth can support is a long-standing one that becomes more intense as the world's population—and our use of natural resources—keeps booming.
This week, two conflicting projections of the world's future population were released. As National Geographic's Rob Kunzig writes here, a new United Nations and University of Washington study in the journal Sciencesays it's highly likely we'll see 9.6 billion Earthlings by 2050, and up to 11 billion or more by 2100. These researchers used a new "probabalistic" statistical method that establishes a specific range of uncertainty around their results. Another study in the journal Global Environmental Changeprojects that the global population will peak at 9.4 billion later this century and fall below 9 billion by 2100, based on a survey of population experts. Who is right? We'll know in a hundred years.
Population debates like this are why, in 2011, National Geographic published a series called "7 Billion" on world population, its trends, implications, and future. After years of examining global environmental issues such as climate change, energy, food supply, and freshwater, we thought the time was ripe for a deep discussion of people and how we are connected to all these other issues—issues that are getting increased attention today, amid the new population projections.
After all, how many of us there are, how many children we have, how long we live, and where and how we live affect virtually every aspect of the planet upon which we rely to survive: the land, oceans, fisheries, forests, wildlife, grasslands, rivers and lakes, groundwater, air quality, atmosphere, weather, and climate.
World population passed 7 billion on October 31, 2011, according to the United Nations. Just who the 7 billionth person was and where he or she was born remain a mystery; there is no actual cadre of census takers who go house to house in every country, counting people.Instead, population estimates are made by most national governments and international organizations such as the UN. These estimates are based on assumptions about existing population size and expectations of fertility, mortality, and migration in a geographic area.
We've been on a big growth spurt during the past century or so. In 1900, demographers had the world's population at 1.6 billion, in 1950 it was about 2.5 billion, by 2000 it was more than 6 billion. Now, there are about 7.2 billion of us.
In recent years we've been adding about a billion people every 12 or 13 years or so. Precisely how many of us are here right now is also a matter of debate, depending on whom you consult:The United Nations offers a range of current population figures and trends, the U.S. Census Bureauhas its own estimate, and the Population Reference Bureau also tracks us.
The new UN study out this week projects that the world's population growth may not stop any time soon. That is a reversal from estimates done five years ago, when demographers—people who study population trends—were projecting that by 2045, world population likely would reach about 9 billion and begin to level off soon after.
But now, the UN researchers who published these new projections in the journal Science say that a flattening of population growth is not going to happen soon without rapid fertility declines—or a reduction in the number of children per mother—in most parts of sub-Saharan Africa that are still experiencing rapid population growth. As Rob Kunzig wrote for National Geographic, the new study estimates that "there's an 80 percent chance . . . that the actual number of people in 2100 will be somewhere between 9.6 and 12.3 billion."
A History of Debates Over Population
In a famous 1798 essay, the Reverend Thomas Malthus proposed that human population would grow more rapidly than our ability to grow food, and that eventually we would starve.
He asserted that the population would grow geometrically—1, 2, 4, 8, 16, 32—and that food production would increase only arithmetically—1, 2, 3, 4, 5, 6. So food production would not keep up with our expanding appetites. You might imagine Malthus' scenario on geometric population growth as being like compound interest: A couple have two children and those children each produce two children. Those four children produce two children each tomake eight, and those eight children each have their own two kids, leaving 16 kids in that generation. But worldwide, the current median fertility rate is about 2.5, (or five children between two couples) so, like compound interest, the population numbers can rise even faster.
Ehrlich, a Stanford University population biologist, wrote a 1968 bestseller called The Population Bomb, which warned of mass starvation in the 1970s and 1980s because of overpopulation. Even though he drastically missing that forecast, he continues to argue that humanity is heading for calamity. Ehrlich says the key issue now is not just the number of people on Earth, but a dramatic rise in our recent consumption of natural resources, which Elizabeth Kolbert explored in 2011 in an article called "The Anthropocene—The Age of Man."
As part of this human-dominated era, the past half century also has been referred to as a period of "Great Acceleration" by Will Steffenat International Geosphere-Biosphere Program. Besides a nearly tripling of human population since the end of World War II, our presence has been marked by a dramatic increase in human activity—the damming of rivers, soaring water use, expansion of cropland, increased use of irrigation and fertilizers, a loss of forests, and more motor vehicles. There also has been a sharp rise in the use of coal, oil, and gas, and a rapid increase in the atmosphere of methane and carbon dioxide, greenhouse gases that result from changes in land use and the burning of such fuels.
Measuring Our Rising Impact
As a result of this massive expansion of our presence on Earth, scientists Ehrlich, John Holdren, and Barry Commoner in the early 1970s devised a formula to measure our rising impact, called IPAT, in which (I)mpact equals (P)opulation multiplied by (A)ffluence multiplied by (T)echnology.
The IPAT formula, they said, can help us realize that our cumulative impact on the planet is not just in population numbers, but also in the increasing amount of natural resources each person uses. The graphic above, which visualizes IPAT, shows that the rise in our cumulative impact since 1950—rising population combined with our expanding demand for resources—has been profound.
IPAT is a useful reminder that population, consumption, and technology all help shape our environmental impact, but it shouldn’t be taken too literally. University of California ecologist John Harte has said that IPAT ". . . conveys the notion that population is a linear multiplier. . . . In reality, population plays a much more dynamic and complex role in shaping environmental quality."
One of our biggest impacts is agriculture. Whether we can grow enough food sustainably for an expanding world population also presents an urgent challenge, and this becomes only more so in light of these new population projections. Where will food for an additional 2 to 3 billion people come from when we are already barely keeping up with 7 billion? Such questions underpin a 2014 National Geographic series on the future of food.
Population is not just about numbers of people. Demographers typically focus on three dimensions—fertility, mortality, and migration—when examining population trends. Fertility examines how many children a woman bears in her lifetime, mortality looks at how long we live, and migration focuses on where we live and move. Each of these population qualities influences the nature of our presence and impact across the planet.
Mortality—or birth rates versus death rates—and migration (where we live and move) also affect the structure of population. Living longer can cause a region’s population to increase even if birth rates remain constant. Youthful nations in the Middle East and Africa, where there are more young people than old, struggle to provide sufficient land, food, water, housing, education, and employment for young people. Besides the search for a life with more opportunity elsewhere, migration also is driven by the need to escape political disruption or declining environmental conditions such as chronic drought and food shortages.
A paradox of lower fertility and reduced population growth rates is that as education and affluence improves, consumption of natural resources increases per person. In other words, (as illustrated in the IPAT graphic here) as we get richer, each of us consumes more natural resources and energy, typically carbon-based fuels such as coal, oil, and gas. This can be seen in consumption patterns that include higher protein foods such as meat and dairy, more consumer goods, bigger houses, more vehicles, and more air travel.
Those of us reading this article are among an elite crowd of Earthlings. We have reliable electricity, access to Internet-connected computers and phones, and time available to contemplate these issues.
As World Bank Vice President Rachel Kyte told Marianne Lavelle ofNational Geographiclast year, "It is energy that lights the lamp that lets you do your homework, that keeps the heat on in a hospital, that lights the small businesses where most people work. Without energy, there is no economic growth, there is no dynamism, and there is no opportunity."
Improved education, especially for girls, is cited as a key driver of declining family size. Having light at night can become a gateway to better education for millions of young people and the realization that opportunities and choices besides bearing many children can await.
So when we debate population, it's important to also discuss the impact—the how we live—of the population equation. While new projections of even higher world population in the decades ahead are cause for concern, we should be equally concerned about—and be willing to address—the increasing effects of resource consumption and its waste.( National Geographic 2014)